Soil stabilisation and solidification
The use of lime, cement or other binder materials to geotechnically improve areas of weak soil into a construction material is an established and extremely cost-effective construction method. Virtually any soil found on site can be improved for bulk fill applications and to build roads, pavements, embankments, reinforced earth structures, railways, housings and industrial units.
By rehabilitating natural materials in situ, construction can be carried out cost-effectively and quickly. Many years of experience has confirmed this technique as the only viable option for treating weak soils and it has been endorsed by the Highways Agency since 1976. Rising landfill costs have made this option a must for all contractors.
Further information is in the publication The Essential Guide to the Remediation of Brownfield Land:
This document provides guidance on the use of Stabilisation/Solidification (S/S) for the remediation of land affected by contamination, as commonly found on brownfield land or derelict sites.
In situ treatment is typically much more cost-effective than traditional ‘dig and dump’ methods, which incur the cost of vehicle movements, landfill taxes and the importation of virgin aggregate. Treated soils can typically be designed to be stiffer than conventional granular materials, leading to reduced thickness designs for foundations and/or subsequent pavement layers.
Soil stabilisation can shorten construction periods by minimising site preparation requirements, tipping and import activities. The process also enables wet ground to be dried and strengthened, ready for immediate use. The addition of quicklime, for instance, instantly dries up wet clays and allows extended working in wet conditions and into the winter.
Importation of large quantities of valuable resources to site, such as Type 1 sub base materials, can be completely avoided by treating in situ soils, using a quick and simple treatment process, to achieve equivalent or higher levels of structural stiffness.
Conventional ground improvement techniques involve the excavation and removal of inappropriate materials, followed by the importation of large quantities of virgin aggregates. Associated construction activities and vehicle movements – which can run to hundreds or even thousands for large projects – can be replaced by the importation and in situ mixing of small quantities of cementitious powders. The result is lower cost, lower congestion and less neighbour conflict.
Avoidance of landfill tax
Soil stabilisation uses in situ soils already available on site. These are improved to give the properties required for construction. This can vary from a simple process to enable use in landscaping or embankments right through to use in structural applications. As all available soils can be used, tipping is virtually eliminated as well as associated tipping charges.